1. Field
One embodiment of the invention relates to a liquid leak sensing structure for sensing a liquid leak in a liquid-using apparatus, for example, to a liquid leak sensing structure capable of absorbing a leaking liquid.
2. Description of the Related Art
In recent years, a small-sized, high-output fuel cell device that does not have to be charged is attracting a great deal of attention as the power supply of a portable computer or that of another type of electronic apparatus. An example of such a fuel cell device is a direct methanol fuel cell (DMFC) which uses an aqueous solution of methanol as fuel.
A recent electronic apparatus is provided with a cooling device that uses a liquid to efficiently cool an electronic component (such as a CPU). The liquid the cooling device uses is, for example, an antifreeze solution or water.
As can be seen from the above, many of the recently-developed electronic apparatuses include liquid-using devices inside their casings. Under the circumstances, it may happen that a liquid will leak inside the casings.
A water leakage detecting device adapted for a fuel cell is known as a structure for sensing a liquid leaking from a fuel cell device. The water leakage detecting device detects cooling water leaking from a fuel cell stack. This type of detecting device is described in Jpn. Pat. Appln. KOKAI Publication No. 2002-164070, for example. The detecting device described in this KOKAI Publication No. 2002-164070 comprises a casing having an inclined bottom surface, and a moisture detector provided at the lower end of the bottom surface.
On the other hand, a fuel cell system provided with a water-absorbing member is described in Jpn. Pat. Appln. KOKAI Publication No. 2000-331699. The water-absorbing member described in KOKAI Publication No. 2000-331699 is provided between a discharge port from which a cathode discharge gas is discharged and a supply port from which an oxidizer is supplied. By use of condensed water collected at the discharge port of the cathode discharge gas, the water-absorbing member humidifies the oxidizer when this oxidizer passes through the supply port. Accordingly, the electrolyte films between the anode and the cathode are kept wet.
In the case of the detecting device described in KOKAI Publication No. 2002-164070, a liquid leaking from the fuel cell stack is detected by a moisture detector. However, if the amount of water the moisture detector detects is too large, the liquid may leak out of the casing.
The fuel cell system described in Jpn. Pat. Appln. KOKAI Publication No. 2000-331699 is not provided with a leaking liquid sensor. If a liquid leakage occurs in this type of fuel cell system, this state is not sensed.